Add CRUD operation to work with repository issues

Hi, I have add and tested some features I would like to have in the main stream of the project. I really like it so, thanks for it. These are the changes.

Additions:
  * Add files to .gitignore for working with eclipse based IDEs.
  * Add new params argument when creating a new Request to allow query parameters in url.
  * Add issues operations (Create/Retrieve/Update/Delete and List). List operation can use filters as query params.

Thanks again and greetings
David